1. Field of the Invention
The present invention relates to a clamping arrangement for the clamping engagement of implements, especially dental instruments, consisting of a mounting sleeve which is rotatably supported within a handpiece, and which is connected with a rotary drive, and which possesses clamping elements acting in a radially inward direction against the shank of the instrument which is inserted into the mounting sleeve. The handpiece can relate to a straight handpiece or an angled handpiece with an angle headpiece.
2. Discussion of the Prior Art
A clamping arrangement of the type referred to has become known from the disclosure of German Petty Pat. No. 18 73 237 and German Laid-Open Patent Application No. 23 42 680. In each of these known clamping arrangements, the mounting sleeve consists of a tubular collet which is provided with elongated slots. In this manner are there formed resilient clamping tongues intermediate the longitudinal slots which, on their part, form the clamping elements. The clamping elements which are acted upon by the external spring element are essentially constructed integrally with the mounting sleeve, which is subject to the disadvantage that upon the wear of the clamping elements, there must be replaced the entire mounting sleeve. Moreover, the cooperation between the external spring element, which is formed by either a helical spring or a resilient sleeve arranged within a metal tube, with the resilient clamping elements which are in themselves resilient, has the result that the clamping force which is exerted onto the inserted shank of the instrument cannot be defined; in essence, cannot be calculated. Finally, in order to impart a length to the clamping elements, which are formed by the resilient clamping tongues, which is sufficient for the secure clamping engagement of the shank of the instrument, the mounting sleeve must, in turn, possess a relatively lengthy construction which increases the dimensions of the handpiece, and necessitates the use of instruments with relatively long shanks.